Curtatoxins. Neurotoxic insecticidal polypeptides isolated from the funnel-web spider Hololena curta.
Three polypeptide neurotoxins (curtatoxins) were isolated from the venom of the spider Hololena curta by reverse-phase high performance liquid chromatography, gel permeation, and ion-exchange chromatography. The purified toxins induced an immediate paralysis in the cricket Acheta domestica that resulted in desiccation and death of the insect within 24-48 h (LD50 congruent to 4-20 micrograms/g); this toxic effect is consistent with irreversible presynaptic neuromuscular blockade. Curtatoxins are a class of sequence-related, cysteine-rich, carboxyl-terminal amidated polypeptides of 36 to 38 amino acid residues. The cysteine residues are conserved at identical sequence positions among these polypeptides and form 4 intramolecular disulfide bonds. Hydropathy calculations show that the toxins have an internal hydrophobic region flanked by hydrophilic and oppositely charged amino- and carboxyl-terminal ends. By analogy to other cysteine-rich arthropod venom proteins, the folded structure of the curtatoxins is likely important for their target specificity and mode of action at the neuromuscular junction.
Stapleton
A
A
Merrell Dow Research Institute, Cincinnati, Ohio 45215.
Blankenship
D T
DT
Ackermann
B L
BL
Chen
T M
TM
Gorder
G W
GW
Manley
G D
GD
Palfreyman
M G
MG
Coutant
J E
JE
Cardin
A D
AD
D060848:Agatoxins; D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006135:Gryllidae; D007928:Lethal Dose 50; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000302:isolation & purification* / Q000633:toxicity; D009498:Neurotoxins / Q000302:isolation & purification*; D011487:Protein Conformation; D013112:Spiders; D013329:Structure-Activity Relationship
D060848:Agatoxins; D009479:Neuropeptides; D009498:Neurotoxins; C062739:Mu-agatoxin-Hc1b; C062738:curtatoxin I; C062740:curtatoxin III